Bleaching and detergent compositions

ABSTRACT

BLEACHING AND DETERGENT COMPOSITIONS COMPRISING A WATER-SOLUBLE PEROXIDE COMPOUND AND AND AN ACTIVATOR COMPRISING AN N-BENZOYLIMIDAZOLE.

United States Patent 3,640,874 BLEACHING AND DETERGENT COMPOSITIONS Frederick William Gray, Summit, N.J., assignor to Colgate-Palmolive Company, New York, N.Y. NorDrawing. Filed May 28, 1969, Ser. No. 828,782 Int. Cl. (111d 7/54 U.S.,.Cl. 25295 15 Claims ABSTRACT OF THE DISCLOSURE Bleaching and detergent compositions comprising a water-soluble peroxide compound and an activator comprising an N-benzoylimidazole.

The present invention relates in general to compositions advantageously adapted for use in connection with fabric washing and bleaching operations and the like and in particular, to the provision of specific compounds and compositions for such purposes.

, The utilization of bleaching agents in conjunction with fabriewashing operations is of course well-established practice if not a recognized necessity. Thus, many of the commercially available detergent formulations have incorporate d therein pre-determined quantities of bleaching agent as an essential ingredient; compounds provided for s uchfpu'rposes are well-known in the art being extensively described in the published literature both patent and otherwisei'As specific examples of, bleaching agents found to be particularly" suitable in practice there may be mentioned the chlorine bleaches e.g., the alkali metal hypochlorites; active oxygen releasing compounds e.g., inorganic persalts such as perborates, percarbonates, perphosphates, persilicates, persulfates, hydrogen peroxide, sodium peroxide and the like. As a general proposition, bleaching agents of the peroxide type are found to be particularly beneficial as regards capability of providing a fabric, having a softer hand, improved absorbency, permanency of whiteness and the like. In contra-distinction, other types of bleaching materials currently enjoying relatively widespread commercial exploitation display a pronounced tendency to yield a fabric possessed of sub optimum. resistance to discolorations upon aging i .e., manifest a fyellowiugf tendency. Moreover, fabrics sotr'eated'invia'r'iablyexhibit considerable loss in strength properties with the consequence that frequency of bleaching-may bes'uch as .to curtail the useful life of the fabric material: v

' Despite themanifold advantages found to inhere in the use of, bleaching agents of the active oxygen releasing type, such materials nevertheless suffer from the rather seriousfdrawback that optimum realization of their benefici'al propertieslcan be obtained ordinarily solely with the use of'elevated'temperatures i.e., in excess of about 185 E. More specifically, temperature values in the neighborhoodof 195 Rand higher are found to be necessary in practice in order to achieve feasible levels of bleaching activity with; peroxide compounds. The aforedescribed temperature dependency of the peroxide bleaches and especially those of the persalt type represents a rather serious shortcoming inview of the popular public use of washing machines at temperatures ranging from about 120 R-toabout 140 F. as" well below those temperatures necessary to render bleaching agents of the peroxide type adequately efiective for even normal household purposes. Consequently, in those instances wherein relatively high orders of bleaching activity are mandatory but at reduced temperature ranges, the use of bleaching agents other than those -of the peroxide type is normally indicated if not required. Despite the attendant disadvantage necessarily involved with respect to discoloration, possible impairment of fabric strength, discoloration, and the like.

In order to exploit the many advantageous features characterizing bleaching agents of the peroxide type, considerable industrial activity has focused on the research and development of means whereby to expand the range of efficacious use of such compounds to the lower temperature ranges and particularly to temperatures within the range from about F. to F.

Perhaps paramount among the techniques thus. far promulgated for such purposes are those involving as an essential expedient the use of the peroxide bleaching agent in conjunction with one or more auxiliary agents the latter being specifically devised to function in an activating capacity whereby to augment or otherwise enhance the bleaching level of the peroxide material to the extent of permitting its effective use within the lower temperature ranges.

Although the precise mechanism by which activator compounds of this type function is not self-evident, it has nevertheless been postulated by way of general hypothesis that acti'vator-peroxide interaction leads to the formation of intermediate species which in themselves comprise effective bleaching means. Viewed in this aspect, it will be apparent that the activator peroxide components provide in effect a precursor system by Which the in situ generation of species capable of providing effective bleaching action is made possible. Thus for example many of the activator compounds heretofore described in the art comprise acylated molecules of various types which, again, according to theoretical exposition purportedly form peracid species as a result of interaction with the peroxide bleaching agent. It is further theorized, as an auxiliary to the foregoing that the overall effectiveness of the activator would be directly related to and thus a function of the strength of the peracid subsequently evolved. Thus, the relative acid strength is indicated by the pKa of such acid. Regardless of the theory involved, actual experience establishes unequivocally that the use of the activator compounds of the aforedescribed type leads to the obtention of highly accelerated bleaching rates.

Although the vast majority of activator compounds thus far promulgated in the art have proved eminently satisfactory, their use is nevertheless found to be subject to one or more serious disadvantages. Perhaps the primary objection relates to their pronounced tendency to injure, impair, or otherwise deleteriously affect the coloring agent present in many dyed fabrics selected for treatment. As will be appreciated, the intolerable tendency of many activators to exhibit such behavior towards dyed goods has led to discontinuance of their use despite other beneficial properties such as stability on aging, etc. Moreover, remedial techniques thus far promulgated and based upon the use of further additives specifically derived to ameliorate the foregoing problems provide marginal net advantage since the attendant disadvantages are often of such magnitude as to vitiate any advantage which might othterwise accure.

In accordance with the discovery forming the basis of the present invention it has been ascertained that a highly delimited class of compounds can, under specified conditions, be advantageously employed in connection with bleaching and detergent operations whereby to permit significant enhancement in bleaching activity absent problems associated with color damage.

Thus, a primary object of the present invention resides in the provision of activator compounds specifically and advantageously adapted for conjoint use with peroxide bleaching agents in bleaching and washing compositions wherein the foregoing disadvantages are eliminated or at least mitigated to a substantial extent.

Another object of the present invention resides in the provision of activator compounds substantially devoid of any tendency to deleteriously affect or otherwise impair the color quality, properties etc. of dyed goods.

Yet another object of the present invention resides in the provision of activator compounds capable of augmenting the bleaching capacity of peroxide compounds to the extent of permitting the efficacious use of such peroxides at relatively moderate temperatures.

A further object of the present invention resides in the provision of activator compounds capable of syngeristically enhancing the bleaching activity of peroxide compounds despite the employment of such activator compound in minor concentrations.

A still further object of the present invention resides in the provision of activator compounds capable of yielding fabric materials subsequent to washing and bleaching having satisfactory absorbency, softness of hand, etc. and possessed of superior resistance to discoloration during Wash cycle and upon aging. Other objects and advantages of the present invention will become more apparent hereinafter as the description proceeds.

The attainment of the foregoing and related objects is made possible in accordance with the present invention which in its broader aspects includes the provision of bleaching compositions containing as essential ingredients (a) a water-soluble stable, peroxide bleaching agent and (b) an N-benzoylimidazole the mole ratio of (a) to (b) being at least 1:5.1. The imidazole compound may, for convenience, be represented according to the following structural formula:

CH-N ea in It will be further understood that the aforedepicted N-benzoylimidazole molecule may further contain one or more substituent groups the salient requirement being that any such group be devoid of any tendency to deleteriously affect or otherwise impair, for example, the activator capabilities of such compounds. Thus, inert and inoccuous groups such as typied by alkyl, halo, loweralkoxy, amino e.g., monoand di-loweralkylamino such as dimethylamino, diethylamino etc., nitro and the like may be present as substituents upon either of the benzoyl or imidazole moieties. Thus, specific examples of N-benzoylimidazole compounds falling within the foregoing formula definition and found to provide pronounced advantage in the relationships contemplated by the subject invention include, without necessary limitation:

Thus, the language N-benzoylimidazole is to be accorded a meaning and significance in the context of the present invention consistent with the foregoing definition. The benzoylimidazole compounds contemplated for use herein may be readily and conveniently prepared according to etc.

1 procedures well 'known in the art; in this connection, references are made to the publications of M. Caplow and W. P. Jencks, Biochemistry 1, 883 (1962) and 0. Gemgross, Berichte 46, 1908 (1913) which describe the reaction of imidazole with aliphatic and aromatic carboxylic acid chlorides.

As indicated hereinbefore, it is critically imperative for realization of the advantages provided by the present invention that the benzoylimidazole compound be employed in such quantities as to yield a peroxide-imidazole mol ratio of at least 1.5 :1. Thus, experimental evidence indicates that even slight departures from the aforestipulated values i.e., less than the prescribed minimum substantially vitiates any possibility of obtaining a bleaching composition adapted for use in connection with the treatment of dyed goods absent any substantial risk of injury to the latter. Thus, and as will be illustrated in the procedures exemplified hereinafter, the utilization of equimolar concentrations of peroxide and activator under normal conditions of use, leads to severe and intolerable injury to dyed fabrics. The upper limiting value of peroxide-imidazole is not particularly critical being a function primarily of economic considerations. In any event, it is found that the broad spectrum of bleaching and/or washing problems likely to be encountered in practice can be effectively negotiated by the use of peroxide-imidazole mole ratios within the range of 1.5 to 15 with a range of 1.5 to 10 being particularly preferred.

The compositions contemplated by the present invention may comprise simply a mixture of the aforedescribed benzoylimidazole activator compound and peroxide bleaching agent. Any of the peroxide compounds conventionally employed in the art as bleaching agents are suitable for use herein with typical examples including, without necessary limitation, inorganic persalts such as typified by perborates, percarbonates, perphosphates, persilicates, persulfates, hydrogen peroxide, sodium peroxide and the like. As will be appreciated, specific circumstances may well serve to dictate the use of a specific type of peroxide compound, e.g., considerations associated with compatibility, bleaching activity active oxygen content etc. In any event, particularly beneficial results are obtained with the use of the alkali metal perborates such as sodium perborate, compounds of this type having been found to permit the attainment of optimum performance as regards bleaching capacity, concentration efficiency and the like.

Additionally, the present invention contemplates the employment of either or both of the imidazole and peroxide compounds in admixture comprising two or more the advisability of so proceeding depending primarily upon the requirements of the processor. In any event, this particular expedient affords to the formulator effective means whereby to capitalize on the beneficial propertles characterizing each of a plurality of imidazole and/ or peroxide compounds. When provided in the form of a simple bleach composition, the involved ingredients may comprise simply a mixture of the peroxide and imidazole compound within the relative molar quantities stated. Other ingredients may be included in minor amounts i.e., from 0 to 5% and preferably from 0.1% to 3% by weight of composition such ingredients including without necessary limitation, phosphates to control pH, olfactory agents, optical brighteners and dyes etc. Where manufacture of the bleach composition in the form of a tablet is contemplated, materials such as typified by corn starch may be added to expedite breakup of the tablet. Optional ingredients of the foregoing type will be discussed hereinafter in greater detail.

Alternatively, the compositions of the present inventlon may be provided in the form of a built detergent composition. Any of the organic detergent materials promulgated in the art for use in relationships of the type described may be employed in the compositions described herein; accordingly, the detergent component may be of the anionic, non-ionic, cationic or amphoteric types.

Suitable anionic surface active agents include those detergent compounds which contain an organic hydrophobic group as well as an anionic solubilizing group. Typical of anionic solubilizing groups include sulfonate, sulfate, carboxylate, phosphonate, and phosphate. Examples of suitable anionic detergents falling within the scope of the invention include the soaps e.g., the water-soluble salts of higher fatty acids or resin acids the latter being derived from, for example, fats, oils and waxes of animal, vegetable or marine origin e.g., the sodium soaps of tallow, grease, coconut oil, tall oil, as well as mixtures comprising two or more of the foregoing; the sulfated and sulfonated synthetic detergents, particularly those having from 8 to 26 carbon atoms and preferably from 12 to 22 carbon atoms per molecule.

As examples of suitable synthetic anionic detergents there may be mentioned the higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates containing from 10 to 16 carbon atoms in the alkyl group, the latter being either straight or branch chain e.g., the sodium salts of decyl, undecyl, dodecyl (lauryl) tridecyl, tetradecyl, pentadecyl, hexadecyl, benzene sulfonate as well as the higher alkyl toluene, xylene, and phenol sulfonates; aromatic tallow (ethenoxy) ether sulfonates, alkyl naphthalene sulfonate, ammonium diamyl naphthalene sulfonate, and sodium dinonyl naphthalene sulfonate. Other anionic detergents include the olefin sulfonates, including long-chain alkene sulfonates, long-chain hydroxyalkane sulfonates or mixtures of alkene sulfonates and hydroxyalkane sulfonates. The olefin sulfonate detergents may be prepared in known manner as by the reaction of S With long-chain olefins the latter having from 8 to 25 and preferably 12 to 21 carbon atoms such olefins corresponding to the following formula RCHCHR wherein R is alkyl and R is alkyl or hydrogen, to produce a mixture of sultones and alkanesulfonic acids. The latter mixture is then suitably treated to convert the sultones to sulfonates. Examples of other sulfate or sulfonate detergents include paraflin sulfonates e.g., the reaction products of alpha olefins and bisulfites, e.g., sodium bisulfite, such as primary paraffin sulfonates of about 10 to 20 and preferably to carbon atoms; sulfates of higher alcohols; salts of alpha-sulfofatty esters e.g., of about 10 to 20 carbon atoms such as methyl, alpha-sulfomyristate or alpha-sulfotallowate. Examples of sulfates of higher alcohols include without necessary limitation sodium lauryl sulfate, sodium tallow alcohol sulfate etc. Turkey Red Oil or other sulfated oils or sulfates of monoor diglycerides of fatty acids e.g., stearic monoglyceride monosulfate, allyl poly (ethenoxy) ether sulfates such as the sulfates of the condensation products of ethylene oxide and lauryl alcohol (usually having from one to 5 ethenoxy groups per molecule); lauryl or other higher alkyl glyceryl ether sulfonates of the condensation products of ethylene oxide and nonyl phenol (usually containing from 1 to 20 oxy ethylene groups per molecule and preferably from 2 to 12).

Suitable anionic detergents additionally include the acyl sarcosinates (e.g., sodium lauroylsarcosinate) the acyl esters (e.g., oleic acid esters) of isothionates and the acyl N-methyl taurides (e.g., potassium N-methyl lauryl or oleyl tauride).

The most highly preferred water soluble anionic detergent compounds comprise the ammonium and substituted ammonium (e.g., the monodiand triethanol amine), a1- kali metal (such as sodium and potassium) and alkaline earth metal (such as calcium and magnesium), salts of the higher alkyl benzene sulfonates, olefin sulfonates, the higher alkyl sulfates and the higher fatty acid monoglyceride sulfates. The deter-gent salt compound selected in a particular instance will depend, inter alia upon the nature of the formulation being prepared as well as the relative proportions of ingredients.

Non-anionic surface-active agents suitable for use herein include those compounds containing both an organic hydrophobic moiety and a hydrophilic group which is a reaction product of a solubilizing group such as carboxylate, hydroxyl, amido or amino with ethylene oxide or with the polyhydration product thereof, polyethylene glycol etc. Examples of non-anionic detergent compounds suitable for use include the condensation products of alkyl phenol with ethylene oxide e.g., the reaction product of isooctyl phenol with about 6 to 30 ethylene oxide units; condensation rpoducts of alkyl thiophenols with 10 to 15 ethylene oxide units; condensation products of higher fatty alcohols such as tridecyl alcohol with ethylene oxide; ethylene oxide addenda of mono-esters of hexahydric alcohols and inner ethers thereof such as sorbitan monolaurate sorbitol mono-oleate mannitan monopalmitate and the condensation products of polypropylene glycol with ethylene oxide.

Cationic surface active agents may also be employed; these compounds characteristically comprise surface active detergent compounds which contain an organic hydrophobic group and a cationic solubilizing group. Typical cationic solubilizing group include amine and quaternary groups.

As specific representive of cationic surface-active agents, there may be mentioned diamines such as those corresponding to the following structural formula:

wherein R represents an alkyl group of about 12 to 22 carbon atoms e.g., N-2-aminoethyl stearyl amine N-2-aminoethylmyristyl amine; amido-linked amines such as those corresponding to the following structural formula:

wherein R represents alkyl of about 9-20 carbon atoms e.g., N-Z-aminoethyl-stearyl amide and N-aminoethylmyristyl amide; quaternary ammonium compounds wherein typically one of the groups bonded to the nitrogen atoms is an alkyl group of about 12 to 18 carbon atoms and the other alkyl substituents contain from 1 to 3 carbon atoms which may contain further substituent group of an inert nature such as phenyl and there is present an anion such as halogen, acetate, methosulfate etc. Specific representives of the aforedescribed class of compound include without necessary limitation ethyl-dimethyl-stearyl ammonium chloride, tetradecyl ammonium chloride trimethyl-stearyl-ammonium chloride, trimethyl-cetyl ammonium bromide, dimethyl-ethyl dilauryl ammonium chloride, dimethyl-propyl-myristyl ammonium chloride, benzyl-dimethyl-stearyl ammonium chloride as well as the corresponding methosulfates and acetates.

Amphoteric detergents may likewise be employed to advantage in the composition described herein i.e., detergent materials containing both an anionic and a cationic group as well as a hydrophobic organic group which is advantageously a higher aliphatic radical e.g., containing from 10 to 20 carbon atoms. Specific representatives include the N-long-chain alkyl aminocarboxylic acids which, for convenience, may be represented according to the following structural formula:

1112 R--NR-C o o M the N-long-chain alkyl imino-dicarboxylic acids which may be represented according to the following structural formula:

RN (R'COOM) z and the N-long chain alkyl betaines of the formula a R-I IRC o o wherein R represents a long-chain alkyl group of about 10 to 20 carbon atoms R represents a divalent radical joining the amino and carboxyl portions of an amino acid e.g., an alkylene radical of 1 to 4 carbon atoms; M represents hydrogen or a salt-forming metal R represents hydrogen or another monovalent substituent, e.g., methyl or other lower alkyl containing from 1 to 4 caI- bon atoms and R and R represent monovalent substituents joined to the nitrogen by carbon-to-nitrogen bonds e.g., methyl or other lower alkyl substituent. Specific examples of amphoteric detergents include the N- alkyl-beta-amino propionic acid, N-alkyl-beta imino dipropionic acid and N-alkyl N,N-dimethyl glycine; the alkyl group may be for example that derived from coco fatty alcohol, lauryl alcohol; myristyl alcohol or alternatively a lauryl-myristyl mixture, hydrogenated tallow alcohol, cetyl, stearyl, or blends of such alcohols. The substituted aminopropionic and iminodipropionic acids are often provided in the form of the sodium or other salt forms which may likewise be employed in the practice of the present invention. Examples of other amphoteric detergents are the fatty imidazolines such as those prepared by reacting a long-chain fatty acid containing from about to carbon atoms with diethylene triamine and mono-halo-carboxylic acid having 2 to 6 carbon atoms e.g., 1 coco-S-hydroxyethyl-5-carboxymethylimidazoline, betaines containing a sulfonic group instead of the carboxylic group; betaines in which the long-chain substitutent is joined to the carboxyl group without an intervening nitrogen atom, e.g., inner salts of 2-trimethylamino fatty acids such as 2-trimethylaminolauric acid as well as compounds of the aforementioned type in which the nitrogen atom is replaced by phosphorous.

Detergents of the type enumerated hereinbefore may be employed in the compositions described herein in amounts varying over a relatively wide range; in any event, the particular quantity selected is not especially critical depending primarily upon the requirements of the formulator i.e., the nature of the detergent problem likely to be encountered in practice having reference to the use contemplated. Thus, where low-foaming characteristics are desired, the non-ionics prove particularly effective; alternatively, the cationics prove beneficial in applications requiring effective germ-killing capabilities since detergents of this type, in many instances, possess a high order of bacteriostatic activity. In any event, it has been ascertained that detergent or surfactant quantities in amounts ranging from 0% to by weight are eminently suitable with a range of 2% to 20% being particularly preferred. Moreover, it will be understood that peculiar and extraordinary circumstances may well dictate departures from the aforedescribed ranges. The present invention, of course, contemplates such developments and accordingly should be so construed.

The detergent compositions, may in addition to the detergent component, contain one or more watersoluble builder salts; included in this group are the inorganic and organic; basic and neutral water soluble salts. The builder salt is employed in amounts ranging up to about 95% i.e., 095% by weight with a range of from about 3 to about 70% by Weight of the composition being preferred. Suitable builders include without necessary limitation,

Trisodium phosphate Tetrasodium pyrophosphate Sodium acid pyrophosphate Sodium tripolyphosphate Sodium monobasic phosphate Sodium dibasic phosphate Sodium hexameta phosphate Sodiub silicates, SiO' /Na O of l/l to 3.2/1 Sodium carbonate Sodium sulfate- Borax etc.

Other organic builders include salts of organic acids and, in particular, the water soluble salts of aminopolycarboxylic acids. The alkali metal salts such as sodium, potassium and lithium; ammonium and substituted ammonium salts such as methylarnmonium, diethanolammonium and triethanolammonium and amine salts such as mono-,diand triethanolamine methylamine, octylamine diethylenetriamine, triethylenetetramine and ethylenediamine are efficacious. The acid portion of the salt can be derived from acids such as nit'rilodiacetic; N-(2-hydroxyethyl) nitrilodiacetic acid, nitrilotriacetic acid (NTA), ethylenediamine tetracetic acid, (EDTA); N-(Z-hydroxyethyl) ethylene diamine triacetic acid; 2-hydroxyethyl iminodiacetic acid; 1,Z-diaminocyclohexanediacetic acid; diethylenetriamine penta-acetic acid and the like. The builder salt is preferably employed in amounts sufficient to yield a pH in water of from 6 to 13 and preferably from 6 to 10.

Particularly preferred for use herein are the watersoluble, alkali metal pyrophosphate builder salts. These salts form water-soluble complexes with calcium and magnesium ions found in hard water and thereby prevent the formation of water-soluble salts which would otherwise tend to deposit upon textiles during the wash cycle. Moreover, such phosphates enhance the detersive efliciency of non-anionic detergents and aid in controlling sudsing, while keeping soil suspended in the washing both after its removal from the soiled textiles. It will likewise be understood that mixtures comprising two or more of the aforementioned builder salts may be employed depending, as stated, on the particular requirements of the formulator. Preferred compositions advantageously contain a hydrophobic colloidal cellulosic soil-suspending agent of a type which is soluble or dispersible in water. The conjoint use of the cellulosic compound and polyvinyl alcohol is found to be particularly effective as regards soilsuspension properties during the washing of a wide variety of fabrics including both cotton and synthetic fibers such as cotton, dacron, and resin-treated cottons. The soilsuspending agent can be employed in amounts ranging from 0 to 3% by weight of the composition solids with a range of 0.1 to 2% being particularly preferred. Cellulosic compounds found to be particularly suitable in this regard comprise the alkali metal salts of a carboxy lower alkyl cellulose having up to 3 carbon atoms in the alkyl group such as the sodium and potassium salts of carboxymethylcellulose. Suitable salts are sodium carboxyethylcellulose; the cellulose sulfates and lower alkyl and hydroxyalkylcellulose others such as methyl-ethyl, ethyl, and hydroxyethylcellulose. It should also be pointed out that little in the way of criticality attends the selection of builder salt concentration and thus, thoseranges conventionally prescribed for relationships of the aforedescribed type are eminently suitable.

The desired pH level may be readily achieved by the addition of suitable buffering agents to the composition, such agents being provided either as a solution, dry powder, granules, flakes, etc. The bleaching compositions of the present invention may be employed to optimum advantage at relatively high pH values thereby permitting the conjoint use of common household laundry soaps as well as detergents specifically designed for preventive bleaching of fibrous materials. Of particular usefulness, especially in areas containing high mineral content, is the presence of a chelating agent as for example the sodium salts of the diethylenetriamine pentacetic acid, ethylenediamine tetracetic acid, etc. and/0r magnesium silicate. For the vast majority of bleaching, washing operations a pH within the range of about 6 to about 10 is recommended. I

The following examples are given for purposes of illustration only and are not to be considered as necessarily constituting a limitation on the present invention. All parts and percentages given are by weight unless otherwise indicated.

The critical interdependency characterizing the perborate and N-benzoylimidazole ingredients in terms of effects of relative concentration on bleaching activity and behavior towards dyed goods will be illustrated in the following examples. As emphasized previously, the signal advantage afforded by the present invention can be made readily manifest by a consideration of the data represented as Ab. The data summarized represents a direct evaluation of the yellowing tendency exhibited by the Cannon Blue Percale samples as a result of being subjected to the tergotometer treatment. As will be recognized, any yellowing tendency is tantamount to color-impairment. Whether the fabric in question be colored or otherwise, it will be apparent that it is of critical importance in laundering operations that the detergent solution be devoid of any tendency to impart yellowing to the treated fabric material;.thus, optimum whitening elfects usually characterize-those fabrics which present a bluish-white appearance. Increasing values of Ab, negatively, correspond to greater suppression of yellowing, the numerical indicia assigned providing a relative assessment, in a quantitative sense, of such property.

Reflectance readings are taken both before and after completion of the immersion treatment, the numerical difference therebetween being recorded as A Rd. Increasing values, positively, of A Rd correspond to greater bleaching.

EXAMPLES 1-12 A detergent formula having the following composition is' prepared.

Ingredient: 7 Parts Sodium tripolyphosate 60 Neodol 45-11 1 10 Sodium nitrilotriacetate 5 Carboxymethyl cellulose 0.5 Sodium sulfate 6.3

A polyethoxylated Cir-C alkanol with 11 ethoxy groups.

To 0.82 part samples of the foregoing detergent formula are added sufiicient sodium perborate tetrahydrate and N-benzoylimidazole activator to give the concentrations specified in Table 1. Eachof the compositions thus prepared is addedto a tergotometer receptacle containing one liter of water at 120 F. Three (3) coffee-tea and three (3) Cannon Blue Percale swatches (3" x 6") are used as the wash samples in each instance. After a 10 minute agitated wash at 120 F., the test swatches are rinsed and dried. The instrumental readings are obtained with a Gardner Color Difference Meter, the Rd and b values for each test swatch being obtained before and after the bleach treatment. The'results for the three test swatches are averaged and the calculated A Rd and Ab data are givenin the table.

EXAMPLES 13-16 A spray dried detergent formula having the following composition is prepared.

Ingredient: Parts Sodium tripolyphosphate 80.0 Linear sodium tridecylbenzenesulfonate 8.5 Sodium sulfate 6.5 Sodium silicate (SiO :Na O=2.4) 1.0 Brightener (Calcofluor White RC) 1 0.40 Brightener (Calcofluor White ALF) 2 0.04 Water 3.0

1 Calcofiuor White RC Cone. (Stilibeno 4) NHQ 4,4-bis (4-anilino45-rnorphliue-5-triazin-2-ylamino)-2,2 stilbenedlsulfonic acid, disodium-salt.

2 Calcofluor White ALF 2-Styrylnaph th (1,2) oxazoie;

To 0.82 part samples of the foregoing detergent are added sufiicient sodium perboate tetrahydrate and N-benzoylimidazole activator to give the concentration specified in Table II. Each of the compositions thus prepared is added TABLE I Sod. Cannon blue Benzolylperborate Active Mole ratio, percale Example imidazole tetrahydrate oxygen perborate to Coffee-tea, No. (p.p.m.) (p.p.rn.) (p.p.'m.) imidazole A Rd A Rd A b None 10 +2. 2 1. 4 --1. 6 .do. 462 48 +3.6 0.5 1.2 116 100 10 1:1 +8.0 +0. 1 -1. 3 173 154 16 1:1 +9. 6 +9.], 4. 8 620 462 "48 1:1 +12. 5 +9. 9 +13. 0 173 231 24 1. 5:1 +9. 1 +0. 9 +1. 0 173 270 28 1. 75:1 +9.0 1. 1 0. 2 173 308 32 221 +8. 7 -1. 9 0. 8 173 385 40 2. 5:1 +8. 1 0. 6 0. 5 173 462 48 3:1 +8. 7 0. 8 1. 7 173 1, 232' 128 8: 1 +8. 8 0. 6 1. 1 462 48 2:1 +9. 1 +0. 1 0. 4

to a beaker containing one liter of water at F. Three (3') coifee-tea'and three -(3) Cannon Blue Percale swatches (3" x 6") are introduced into the solution in each instance. The test swatches are allowed to soak without agitation for a period of 18 hours, the bath normally attaining room temperature (76 F.) in this period of time. The test swatches are then rinsed, dried and the ARd and Ab data given in Table H is obtained by use of a Garden Color Difference Meter.

TABLE II Sod. Cannon blue Benzolylperborate Active Mole ratio, percale Example imldazole tetrahydrate oxygen perborate to Coffee-tea, No. (p.p.m.) (p.p.m.) (p.p.m.) ldazole A Rd A Rd A (2 None 100 10 3. 7 1. 3 1. 3

it should be emphasized that nothing critical attaches to 10 be employed to advantage where enhanced anti-germithe selection of an upper limiting mole ratio value of perborate to activator, considerations in this regard being primarily of economic significance. However, it is found that a point of diminishing returns will be reached at which further increases in perborate fail to provide commensuate advantage or improvement in results. In any event, the skilled worker is readily capable of determining optimum modes of proceeding in a particular circumstance having reference to the type of peroxide compound employed, N-benzoylimidazole, etc.

EXAMPLES 17-33 The procedure described in connection with Examples 1-12 is repeated except that the N-benzoylimidazole activator compound is replaced with the activator compounds identified in Table 2 in the mole ratios specified.

TABLE 2 Activator Mole ratio Example No.2

17 N-(dmethyl)-benzoylimidazole 2: 1 18. N-(p-nitro)-benzoylimidazole 3: 1 19- N- (p-methyl) -b enzoyllmidazole- 2; 1 20. i N-(p-ch1oro) -b enzoylimidazole 4: 1 21 N-(p-methoxy) -benzoylirnidazole 2:1 22 N-(m-methyl)-benzoylimidazole 3: 1 23 N -(1n-chloro) -benzoylimldazole. 2:1 24 N-(o-chloro)-benzoylimidazole 3:1 25 N -(o-methyl)-benz0yllmldazole 3:1 26 N-(p-methoxy)-benzoyllmidazole 3: 1 27 N-(p-chloro)-benzoylirnidazole 2:1 Z8 N-(m-ehloro)-benzoylimidazole 3: 1 29 N -(p-methyl)-benzoylimidazole 4:1 30 N-(p-nitro)-benzoylimidazolei 2 :1 3L N-(o-chloro)-benzoylimldazole 2:1 32 N-(m-methyl)-benzoylimidazole 2: 1 33 N-(m-fiuoro)-benzoyllmldazole 2 1 The results obtained are similar to those described in Examples 1'12, i.e., in each instance, highly satisfactory bleaching (ARd) levels are obtained in the virtual absence of color impairment when compared to test runs conducted under identical conditions but employing an perborate/activator mole ratio of 1:1.

Results similar to those described in the foregoing examples are obtained when the procedures delineated therein are repeated but employing in lieu of sodium perborate, equivalent amounts of one or more of sodium percarbonate, sodium persilicate, etc. The terminology water-soluble peroxide, persalt, etc. bleaching agent as used herein is intended to connote those compounds which give use to hydrogen peroxide when dissolved in water. Thus, the peroxide compounds contemplated for use herein are believed to contain hydrogen peroxide of crystallization.

Moreover, the favorable properties characterizing the compositions of the present invention seem to be completely independent of the type of detergent compound employed, i.e., whether nonionic, cationic, anionic, zwitterionic, etc. The choice of detergent is purely a matter of discretion lying within the province of the formulator. Thus, in those applications requiring low-foaming properties, nonionic types of detergents would ordinarily be preferred. In contradistinction, cationic detergents may cidal activity is either necessary or desirable.

In addition, the present invention contemplates that mixtures comorising 2 or more of the activator, peroxide and/or detergent components may be recommended in certain instances; in this manner, the beneficial properties characterizing a plurality of such materials may be combined in a single composition.

What is claimed is:

1. A bleach composition consisting essentially of (a) a water soluble, stable, inorganic peroxygen compound, and

(b) an activator selected from the group consisting of N-benzoylimidazole and substituted with lower alkyl, lower alkoxy, nitro, halo, amino and lower alkyl amino and mixtures thereof, the mole ratio of (a) to (b) ranging from 1.5 to 15.

2. A composition according to claim 1 wherein activator is N benzoylimidazole.

3. A composition according to claim 1 wherein activator is N-(p-nitro) -benzoylimidazole.

4. A composition according to claim 1 wherein activator is N-(o-methyl)-benzoylimidazole.

5. A composition according to claim 1 wherein activator is N-(p-methyl)-benzoylimidazole.

6. A composition according to claim 1 wherein activator is N-(p-chloro)-benzoylimidazole.

7. A composition according to claim 1 wherein activator is N-(p-methoxy) benzoylimidazole.

8. A composition according to claim 1 wherein activator is N-(m-methyl) benzoylimidazole.

9. A composition according to claim 1 wherein activator is N-(m-chloro)-benzoylimidazole. I

10. A composition according to claim 1 wherein activator is N-(o-chloro)-benzoylimidazole.

11. A composition according to claim 1 wherein said activator is N-(m-fluoro)-benzoylimidazo1e.

12. A composition according to claim 1 wherein said mole ratio of (a) to (b) is within the range of from about 1.5 to about 10:1.

13. A composition according to claim 1 wherein said peroxygen compound is sodium per-borate tetrahydrate.

14. A composition according to claim 1 further containing a water soluble detergent in amounts ranging from about 2% to about 50% by weight of said composition.

15. A process of bleaching which comprises contacting a material to be bleached with an aqueous solution of the composition of claim 1.

said

said

said

said

said

said

said

said

said

References Cited UNITED STATES PATENTS 3,163,606 12/1964 Viveen et al. 252- X 3,177,148 4/1965 Bright et al 25299 MAYER WEINBLATT, Primary Examiner US. Cl. X.R. 252-1 86 

